Hand metal stamping tool



Jan. 8, 1952 c. A. ROYER 2,581,715

HAND METAL STAMPING TOOL Filed June 20, 1947 ll mmuu: n

Rig Q F INVENTOR.

CELEJIJNE A. B0 YER BY ci i'wa/rfimvri A T IDEA/5Y5 Patented Jan. 8, 1952 HAND METAL STAMPING TOOL Celestine A. Boyer, Champaign, 111., assignor to R. H. Bishop Company, Champaign, 111., a corporation of Illinois Application June 20, 1947, Serial No. 756,033

3 Claims. i

This invention relates to'a hand metal stamping tool for stamping or punching sheet metal.

It particularly relates to a hand tool which can be carried by the workman working on sheet metalv such as tin, for the forming of joints in the making of air ducts and other devices made from relatively light gauge sheet metal.

Hand as well as power operated presses are available for stamping or pressing light gauge sheet metal but such presses are bulky and, of necessity, are maintained in a shop such as a tinsmith shop and the like. The present practice for cutting out sheet metal for the making of joints in sheet metal fabricated products is to first layout with a pencil, chalk or crayon the portion to be cut out of the sheet metal according to the type of joint desired, and then to use sheet metal shears for cutting out the metal. This is a time-consuming process. In addition, it tends to inaccuracies not only in the laying out on the sheet metal but also in following the lay-out lines during the shearing operation. There is known to me no hand tool on the market in which a joint can be cut out of a corner of sheet metal in one operation. It is therefore the principal object of my device to provide a hand operated tool which can be carried by the workman for stamping out or punching out the metal while the workman is on the job.

It is a further object of the invention to provide a tool having sufiicient leverage that the hand stamping operation can be easily accomplished.

In the cross lever or scissors type of tool, care must be taken to avoid slippage of the material upon stamping, cutting or punching. It is an object of my invention to provide a toggle operated lever in connection with the jaws and dies, which holds the material securely in position during the stamping operation.

Other advantages and objects of my invention will become apparent by referring to-the drawings in which Figure 1 is a side view of the device showing the cross lever type of construction.

Figure 2 is an end view of the device looking toward the jaws of the tool.

Figure 3 is a detail of the lever mechanism for holding the metal in place during the stamping operation.

Figure 4 illustrates one type of stamping of sheet metal which is frequently required by tinsmiths.

Referring to the drawings, a pair of lever arms I and 2 are provided which are pivotally attached to each other by means of the bolt 3.

r 2 a a Hand grips 4 and 5 of the scissors type are provided.

The jaw of the device is generally referred to by the numeral 6. To the hand lever arm 2 is attached a table Or shelf extension of the jaw marked I. A similar table or shelf extension 8 is provided attached to the handle I. In the usual construction each lever arm and portion of the jaw is made in one piece. The entire tool is preferably made out of a good grade of steel which is ordinarily used in the manufacture of similar devices, such as cold drawn steel, high tensile steel, and the like.

Detachable dies are attached to the jaws which include the jaw extensions. The upper die 9 is attached to the upper jaw by means of the bolts or screws IE]. The lower die II is attached to the lower jaw by means of the bolts l2. Openings I3 in the dies engage the pins M, the pins I4 being permanently attached to the jaws, in order to fix the proper position of the dies on the jaws before attaching the various screws. or bolts which hold the dies in place.

A separate toggle arranged hand lever is provided for holding the material securely in place during the stamping operation. Referring particularly to Figures 2 and 3, an L-shaped arm I5 is provided having a projection I6 which projection is properly shaped and sharpened for biting into the material and holding it in place. The arm I5 is pivoted at I I to the supporting members I8, supporting members I3 being attached by welding or other means to the table extension 8 of the lower jaw. The hand lever arm I9 is pivotally attached at the point 20 to the arm I5 and the pivot point 20 is spaced from but adjacent the end of arm I9 to which the toggle link 21 is pivotally attached at the point 22. The toggle link 21 is also pivotally attached at point 23 between the supports I8.

In the position shown in Figures 1 and 3, the hand lever is pulled back toward the hand grips 4 and 5 which forces the lever arm I5 downwardly toward the material, and the projection I6 in cooperating with the die l2 holds the material firmly in place. After the material is so held firmly in place the lever arms I and 2 are brought together and the metal is stamped out as indicated in Figure 4. By pushing the lever arm I9 away from the hand grips 4 and 5, the lever I5 is raised and the projection I6 is released from the material.

The handle 19, the toggle link 21 and the pivot points 20, 22 and 23 form a toggle arrangement for pivoting the arm I5 about the pivot II.

It is understood that any type of detachably attached die or punch may be used in the device; The type shown is for stamping out what is commonly referred to among tinsmiths as a Pittsburgh joint. The Pittsburgh joint which is stamped out by the dies is shown in Figure 4. The sheet metal is placed in the jaw 6 and the lever arm l9 operated so that the projection It holds the metal iin place. The handles! and La r'e then brought'together and the dies cutaway portion A, outlined by the dotted lines on Figure 4,

from the portion B, leaving steplike notches in the corner of the sheet metal.

One of the big advantages of my device is its flexibility that any type of die :may "be readily inserted in the hand tool and a separate hand tool does not have to be used for each kind of stamping operation. Also, the dies are readily removed for sharpening or replacement.

Other embodiments of my invention may he made within the following claims.

:Iiclaim as my invention:

1. A hand tool for blanking sheet metal ,com-

prising :a pair of-crossed .hand levers pivotally attached to each other, -'a die-receiving jaw having -.a rface on each of said 'levers,'dies detachably attached to each of said jaw faces, .a first lever pivotally attached to one of said hand levers, a projectiononisaid lever operative with one of said dies holding said metal in place "during said stamping, a "second lever connected with said first lever through a toggle joint for forcing said projection against said metal thereby holding one-of said hand levers adjacent said jaws, the

arm of said jaw extending toward one of said 4 jaw faces having a projection on the extremity of said L operative with said die for holding said metal in place during the stamping operation, the leg of said L-shaped lever pivotally attached between the extremities thereof to one of said hand levers, a lever arm pivotally attached near but spaced from one end to said L-shaped lever, ailiiik pivotally attachedto one of said lever arms, said link pivotally attached "to the extremity of the last mentioned hand lever arm adjacent i't's pivotal point to said L-shaped lever, said .link lever and-said arm lever thereby forming a toggle joint with said L-shaped lever for operating said' l shaped lever and for clamping the metal to be stamped between the projection on said-L-shapedlev'er and the face of said die with i which it is operative therewith.

3. A hand tool for blanking sheet metal comprising 'a pair of crossed handles pivotally connected, a die receiving jaw on each handle, detachable diesiin each-j aw, metal clamping means on one of said handles, said clamping means includinga metalsheet-engaging arm and ,a lever connected through a toggle joint, said lever ac.-

tuating said arm cooperative with ;one .of said dies to :hold said sheet in :placeduring-starnping.

GELESTI'NE A. 'RGYER;

REFERENCES CITED The following references are of record in the file of this patent: UNITED STATES PATENTS Number Name Date 5'3'7j382 Branson "a Apr. 9, 1895 1,677,684 Parsons July 17,1928 1,679,039 Kucera July "31, 1928 1;862,033 Porter June 7, 1932 2,013,574 Miller Sept. 3, 19-35 2,449,839 Brittle Sept. 21, "1948 FOREIGN PATENTS Number Country '"Date 'l'24,'875 Great Britain Apr. 2, -l9-1-8- 670,574

France Nov. 30, 1929- 

